Although John Frusciante is best known as a guitarist with the rock band Red Hot Chili Peppers, he also has an active solo career, having released 11 albums under his own name. His solo recordings include elements ranging from experimental rock and ambient music to New Wave and Electronica.

A Sphere in the Heart of Silence is a collaborative studio album by John Frusciante and future RHCP guitarist Josh Klinghoffer, released on November 23, 2004 on Record Collection. The fifth in a series of six releases Frusciante issued from June 2004 to February 2005, the album is composed mainly of electronica-based material.